Apparatus for forming a multiple web product



H. W. HIRSCHY APPARATUS FOR FORMING A MULTIPLY WEB PRODUCT July l', 19586 Sheets-Sheet l Filed Dec Nm. `M n mM w @y w hw f/ l A A l QN @A s p Mwmw ww m RN W m ,NN MN VIA NN NN IILI HI l 1 I x I H/ NN MN! l |\\\l /m@NQ \1 hm. mlwm www. WN mwl Nn. NNMNQN mm J, Q W wm um, Nw] MN N@ also@July 1, 195s H. w. HlRsHY APPARATUS FOR FORMING A MULTIPLY WEB PRODUCTFiled Dec. 17, 1954 6 Sheets-Sheet 2 NNN H..w. HlRscHY 2,841,202APPARATUS Fox gomme A MULTIPLY WEB PRODUCT July l', 1958 6 Sheets-Sheet3 lFiled Dec. 17, 1954 July l, 1958 H. w. HnscHY 2,841,202

APPARATUS FOR FORMING A MULTIPLY WEB PRODUCT Filed Dec. 17, 1954 6Sheets-Sheet 4 PROJECTION OF MAlN SHEET UNWEAPPED j, jg /4 g5 farla/i2MHz/isc@ gg/60W, 9 @no6/wan@ H. W. HIRSCHY APPARATUS FOR FORMING AMULTIPLY WEB PRODUCT Filed Dec. 17, 1954 July 1, 1 958 6 Sheets-Sheet 5July 1, 1958 H. w. HlRscHY APPARATUS FOR FORMING A MULTIPLY WEB PRODUCT6 Sheets-Sheet 6 Filed Dec. 1'7, 1954 ron FORMING A MULTIPLE WEB PRODUCTHarlan W. Hirschy, Neenah, Wis.,

Clark Corporation, Delaware APPARATUS assignor to Kimberly- Neenah,Wis., a corporation of Application December 17, 1954, Serial No. 476,027

' 6 claims. (ci. 1st- 1.7)`

The present invention is concerned with a method and an apparatus forforming thread and web structures in a continuous manner, and isprimarily directed Vto the manufacture of thread and web products inwhichV means are provided for improving the physical properties of theproduct by controlled orientation of the elements up the product.

While the present invention has applicability to the manufacture o-fnumerous types of products of widely different characteristics, theinvention will be described as it is applied to the field of nonwovenweb and thread textile products. v

`In some fields, nonwoven Webs composed of cotton fibers, rayon bers, ormixtures of various natural or synthetic fibers have very distinctadvantages over woven textile webs. The light weight, softness, and thelow cost of such webs are some of the characteristics which make themuseful as replacements for the considerably heavier and less flexiblecottonA gauze materials. The major drawback to the use of nonwoven webshas, of course,been their inherent lack of strength, when compared witha woven material of the same weight per unit area.

The strength of a nonwoven web in a given direction isV directly relatedto the `relative number of libers of the web extending in thatdirection. With conventional apparatus for forming nonwoven webs, themajority of the bers extend generally in the machine direction of theweb so that the maximum strength occurs lengthwise of the web and muchless strength is obtained in the cross-machine or transverse directionin the web.

For many applications of nonwoven web structures, it is important thatthe transverse strength of the web be comparable to, or even greaterthan, the strength in the machine direction. One practical means foraccomplishing this result is to provide a laminated structure in whichthe fibers of one of the webs are disposed primarily along thelongitudinal direction of the web, and the fibers inpan overlying webarearranged substantially perpendicular to the bers in the first web.

Such products are very diflicult to manufacture, especially as acontinuous operation, although it should be mentioned that somepaperboard cores are made of two plies of paper with the Vmachinedirections of the separate plies at an angle to each other. However,because of the method and apparatus employed in combining the paperplies in this product, the finished core results in a dual helix ofpaper webs in which the maximum strength is neither along thelongitudinal rior the transverse axis of the product.

Some other types of equipment have been suggested for making more nearlyperfect crosslaid webs. such equipment is usually discontinuous inoperation and in any event, operates at an extremely slow speed. Theprovision of an apparatus for manufacturing such Webs ina continuous andrapid manner is oneof the primary Aobjectsof the present invention; v vv makingl However, i

ice

The present invention is also concerned with the provision of methodsand apparatus for making gauzelike web or sheet products from sets ofstrands which are' laid in a cross pattern one on the other. `Otherobjects of the invention include the provision of a method'formanufacturing a strengthened nonwoven web in a continuo-us, rapidprocess, and the provision of novel 'apparatus for continuously laying across sheet or apattern of threads onto a moving supporting surfacewhich may also include, a sheet or a patternrof threads, andeforv crosssheet to provide la continuous crosslaid cutting the product.

The invention also includes the provision of certain structural andoperational features of great importancei in accomplishing the abovestated general objects of 'they invention. i

The present application is a continuation-in-part of my priorapplication, Serial No. 390,402.9, tiled vNovember 3, 1953,-nowabandoned, 1and is assigned to the assignee the sheet, or the directionof the reinforcing strands, i-s` at a substantialand predetermined angleto the direction of movement of the supporting surface, 'to the end thatthe resulting direction of lay willbe' at an angle, alsoV predetermined,and preferably a right angle to the Inachine direction `of the finishedproduct, and'then continu" ously cutting the second helixlaterally' inVa direction parallel to an edge of the supportingsurface.

Several forms of apparatus for carrying out the abovedescribed methodare illustrated in the drawings, in which:

Figure l is a View in perspective ofan laying a sheet material onanother sheet;

Figure 2 is aplanview of the' apparatus shown in Figure l; a

Figure 3 is a fragmentary, somewhat enlarged View of the drum andmandrel assemblyv 'of the apparatus illustrated in the precedingfigures;

Figure 4 is a somewhat schematic view of the mandrel and the two sheetstrained around the mandrel, illustrating the manner inwhich the crosssheet or other medium or other medium;

Figure 5 is an'enlarged, fragmentary mechanism which may be employed;

Figure 6 is an end view of the mandrel in the direction of the mandrelaxis; i

'Figure l7 is an enlarged, fragmentary view of a typical completednonwoven web, the view beingA partially broken away to illustrate thestructure of the component plies;

Figure'S is a somewhat schematic drawing of a machine for applying apattern of threads onto a web;

Figure 9 isa fragmentary View of a gauze-like product which may lbeproduced with the machine shown in Figure8;

Figure 10 is a fragmentary view of an overlapped web structure alsofalling within the scope of the present invention;

Figure ll is a schematic view illustrating the various angularrelationships which occur during thecross: laying of the web, thread, orother mediums, one vupon the other;

Figure 12 is a fragmentary view, partially in section, of an improvedmandrel construction-having especial utility'in connection withapparatus of the general typel shown in Figures land 8;v

view of a cutting apparatus for Figure 13 is anV enlarged sectional viewtaken on the line 13-13 of Figure 12; and

Figure 14 is a perspective view of a particular belt constructionespecially useful in the practice of the invention.

' In Figures 1 and 2, reference numeral 10 indicates generally a frameassembly which supports the various elements in the cross layingassembly. The upper beam sections of the frame 10, indicated at 11, havea pair of angularly disposed shaft supports 12 which tightly engage ashaft 13 extending from a stationary mandrel 14 and hold it againstrotation. The mandrel 14 is provided along a portion of its outersurface with a helical, raised rib 16 to serve as a guide means for anendless exible belt 17 composed of canvas or other exible material. Thebelt 17 is guided onto the surface of the mandrel 14 from a roller 18and extends between the lands providedV by the rib 16; the width of thebelt 17, measured on a line parallel to the axis of the mandrel 14,' isslightly less than the pitch of theV helix provided by the rib 16.

.Forv most types of webs, it will be desirable to use a belt of thisnature in guiding the web around the mandrel, but the presence of thebelt may not be required for webs which can conform to the mandrelsurface without breaking upon the application of suflicient force topull the web about the mandrel. Y

The belt 17 makes at least one complete turn about the stationarymandrel 14 and then is trained over a driven roller 19. The latter has ashaft 21 supported by a block 22 slidably received within a slot of abracket 23 carried by the frame 10. Movement of the block 22 within theslot thus provides a means for adjusting the tension of the belt 17. Thebelt then passes over a roller 24 having a shaft 26 supported within ablock 27 also slidably received in the slot in the bracket 23. Therelative position of the roller 24 with respect to the roller 19 can beadjusted by movement of a rod 28 attached to the block 27.

The belt 17 after being trained around the roller 24 passes over a guideroller 29 located centrally of the frame 10, and is then trained arounda roller 31 located near the base ofthe frame 10. The belt is thenpassed lengthwise of the machine and may be given a half twist so thatit can be trained around a vertically disposed tension roller 32 (Figure2).

The belt 17 is then trained around a second vertical tension roller 33after which it is given another half twist. The belt is then receivedabout a guide roller 35 and tinally passes over the roller 18,completing its oop.

As the belt 17 is moved along the mandrel 14 in the illustratedstructure, it carries with it a longitudinal web or sheet medium 36.This may comprise a sheet of paper or nonwoven fibers, as illustrated,or it may comprise threads, or other material. The medium 36 isconveniently deposited on the belt 17 from a suitable supply means, suchas the roll of sheet material illustrated at 37 in Figures l and 2, andthe apparatus desirably includes a suitably disposed roll 38 for guidingand slightly tensioning the sheet 36 or other medium as it is depositedon the upper surface of the belt 17. The axis of the illustrated supplyroll 37 is parallel to the axis of the belt guide roll 18, and thesupply roll 37 is conveniently disposed a short distance above and tothe rear of the belt guide roll 18.

In the illustrated embodiment of the invention, the width of the sheet36 is comparable to the width of the belt 17 and when the sheet 36 is ofnonwoven material, the fibers in the sheet 36 will lie predominantly inthe machine direction, i. e., lengthwise of the sheet, so that themaximum strength of this sheet is along its long dimension.` Rollers canbe provided for pressing the sheet 36 onto the belt 17, or adhesive.spots may be employed on the sheet for holding it on the belt, butordinarily these are unnecessary, as a thin, nonwoven web will readilybe guided by the surface of a canvas belt.

The mandrel 14 is disposed with it axis substantially coincident withthe axis of a hollow rotating carrier 39, comprising a pair of endtlanges 41 and 42 separated by means of spacers 43. The rim of thecarrier 39 is mounted for rotation on a set of four wheels 44 (Figure 1)which are supported for rotation on a bracket 46 secured to anintermediate portion of the frame 10.

The carrier 39 has a pair of angularly disposed support brackets 47 and48 (Figure 2) which journal a shaft 49 for rotation therein. The shaft49 carries the second medium which is applied, in crosswiserelationship, to the tirst medium during the operation of the apparatus.In the illustrated apparatus, the second medium comprises a sheet 52 ofnonwoven fibers which is unwound from a suitable supply roll 51 disposedon the shaft 49. The bers in the sheet 52 extend predominately along thelength of the sheet so that the maximum strength of the sheet is in thatdirection.

The sheet 52 passes over a guide roller 53 and is then wrapped aroundthe main sheet 36 carried by the belt 17 (Figures 3 and 4). If desired,small spots of adhesive can be provided on the sheet 52 to hold it ontothe sheet 36 until the combined sheets leave the machine. The angularpositions of the roll 51 and the roller 53 are quite critical, and thesupport mechanism for the members 51 and 53 should be adjustable. Whenlaying one web upon another, or when laying a series of cross webs toproduce products of the type shown in Figure l0, freedom from distortionwill be achieved only if the sheet 52 is trained about the mandrel sothat the sheet 52 intersects the sheet 36 (or the belt 17) along acontinuous straight line of intersection extending the full Width of thesheet 52. Thus, the sheet 36 in being pulled across the mandrel 14 formsa helix which moves about the mandrel 14 in a counter-clockwisedirection as viewed from the end of the carrier 39 at which the sheet 36enters. At the same time, the relative movement between the roll 51 andthe mandrel 14 resulting from the rotation of the carrier 39 about themandrel 14, which rotation is also counter-clockwise, as viewed from theend of the carrier at which the sheet enters, wraps the sheet 52 inanother helix which intersects the helix of the sheet 36 at right anglesthereto.

When using the particular apparatus shown in the drawings, the sameangular relationships will be observed where the sheet 52 is replaced bya plurality of threads or other strands, i. e., the points of tangencyof the strands as they are trained labout the helically moving sheet 36will define a straight line parallel to the axis of the mandrel.However, the laying of threads upon webs or other threads permits aconsiderably wider variation in the parameters of the process, and thesewill be discussed in a subsequent portion of this specification.

After the crosswise reinforcing medium, whether of threads or of sheetmaterial, has been applied to the medium trained about the mandrel, thesheet 36 in the structure of Figures l and 2, the crosswise medium, thesheet 52 in the illustrated structure, is continuously slit by means ofa slitting device S4, best illustrated in Figure 5 of the drawings. Asseen in that drawing, the slitting device 54 may comprise a small motor56 which drives a shaft 57 upon which a disc cutter 58 is secured. Theedge of the disc cutter 58 is positioned so that it cuts the laminatedsheets at oneedge of the main sheet 36, parallel to the marginal edge ofthe main sheet 36. The edge of the disc cutter 58 extends into the smallspace provided between the belt 17 and the rib 16, as shown. The cuttingmeans 54 is secured to a stationary part of the frame 10 by means -of asupport arm 59 (Figure 3).

A common drive system is employed to pull the belt 17 across the mandrel14 and to rotate the carrier 39. This drive system may include avariable speed motor 61 which drives a variable speed transmission 62through s a chain and sprocket assemblyf63 (Figure 2).` The output shaftof the transmission 62 operates a speed reducer (not shown) which in-turn is coupled to a sprocket 64 (Figure 1) by means of a chain 66 to'drive the roller 19.

The energization of the motor 61 is controlled by means of a motorcontrol unit 67, electrically connected thereto. A hand operated control68 (Figure 2) provides a means for adjusting the input to the motor. The`shaft of the motor 61 also is coupled to a speed reducer 69 by means ofa chain and sprocket yassembly 70 (not shown in detail), and the outputof the speed reducer 69 is coupled by means of a sprocket and chainassembly 71 to a shaft 72 to which a beveled gear 73 is secured. Thebeveled gear 73 engages an annular gear 74 concentric with the endflange 41 of the drum `39 to rotatethev carrier 39 about an axissubstantially coinciding with the axis of the mandrel 14. i

The means for pulling the belt across the mandrel 14, as well as the-means for driving the carrier 39 illustrated in the drawings, representonly one possible drive system which may be employed, and it will berecognized that various means could be provided to accomplish the sameresults. n

A linished web, as it is delivered by the machine in the vicinity `ofthe roll 19, is 'illustrated in Figure; 7"of the drawings. As seen inthis gure, the underlying sheet 36 has a signilicant proportion of itsfibers aligned in the longitudinal direction of the web, and the crosssheet 52, of slightly greater width than the sheet 36, has its fiberspredominantly in the' direction perpendicular to the direction of thelongitudinal libers in the sheet 36. The laminated web structure can beprinted in spaced areas with suitable adhesives such as vinyl polymers,polyethylene, and the like in order to further increase the strength ofthe laminate according to any of a variety of processes.

A modified form of the invention is illustrated in Figure 8 of thedrawings. In this embodiment of the invention, which is especiallyladapted to the manufacture of cross laid thread products, such asare'illustrated in Figure 9, or to products which combine sheets andreinforcing threads, means are provided to apply a pattern of. threadsina network over a moving web or other medium.- As

seen in Figure 8, `a sheet 81 which maybe a sheet of` nonwoven fabric orother sheet material, is received under a roll 82 whereupon it isguided. onto the surfaceof a moving belt 83 bymeans of a roller 84; As.thesheet 81 and the belt 83 move to the right as seen in Figure 8,

the sheet 81 is overlaidwith a pattern of longitudinalil threads 86which are being constantly supplied from a creelt 87. The thread conesincluded in the creel 87 supply a plurality of series of threads 86which pass through a plurality of guide means 88 arranged to direct thethreads over a iirst guide bar 89 and about a second horizontallydisposed guide bar 91. The threads 86 then pass overa comb array 92,following which the threads are given a coat of adhesive from anapplicator roll 93 in contact with the threads. VA suitable adhesivesuch as a thermoplastic resinons composition is applied to the surfaceof the applicator roll 93 from a roll 94 in=contact therewith. v

After the threads 86 have received a coating of adhesive, the threadreinforced web and the belt83 Ycarrying the web .are guided about astationary, cylindrical mandrel 96 so Yas to form thereon a'lirst helix,as shown.

The belt 83, of course, is continuously pulledl about the` stationarymandrel 96 by means not shown in the drawings.

The mandrel 96 issubstantially coaxial with a. rotating carrier or disc97 which applies threads to the moving web in a direction normal to thedirection of the previously applied threads. In other words, the carrier97 is arranged to wrap additional threads in the form -of helices atright angles to the helices. formed by the previously deposited threadsas those threads'pass about the mandrel. The points of contact in theillustrated em bodiment form equally spaced points on a right circularsection of themandrel, instead of the straight line of'- intersectiondescribed in connection with the previously described embodiment; Aspreviously pointed out, the

line of intersection in the case of thread laying may vary' considerablydepending upon the manner in whichv the threads are received on thesupporting surface.

The carrier 97 supports a plurality of circumferentially spaced conesvof. thread supported on both sides thereof..

The cones 98 feed threads 99 centrallyv of the carrier disc 97 and overan annular series of guide means 101 -ontoy the surface of the movingbelt or sheet; l .As the belt 83 is removed from the mandrel, a slitter102 engages the web to sever the Vcross strands parallel to themarginaledge of the moving sheet.A 1-

The resulting thread reinforced product-is then separated from the belt83, the belt V83`passingr over a .series of.rollers,.including rollers103 :and 104, before returning- The'thread reinforced` to theinlet endyof the machine. product may be then passed about a` heated roller 106in contact with a heat resistant roller 107 in order to cause theadhesive applied to the strands to become more plastic and to flow aboutthe junctions of the longitudinal and transverse threads. With certaintype of adhesives,` a better bond is thereby secured between thevweb'and-1 the pattern ofl threads, but the use of a heated roll orV rollsis optional.

After leaving the surface of the roll 107, the completed productwillnormaly be conveyed, as by the roll 108, to"

a slitting means 109 where the web will be cut into' any desired width.After leaving the slitting means 109, the

web strips are wound about a take-up reel 111`by means of a pair ofwinding rolls 112 and 113. t

It will be appreciated that various 'other mechanical means such asgears, belts, chains, discs or the like may be employed to carrythecross laid material on a path which is coaxial with the axis of themandrel.

More than one layer of sheet material. may be embodied into the finishedproduct. For example, an ad-I ditional sheet or web, ora series ofsheets or webs, may

bev applied to the upper surface of the threads 86, and'l the underlyingsheet or sheets, at any convenient point` prior to the application ofthe threads 99. Similarly,

additional sheets, or even additional sets of longitudinallyt extendingthreads may be applied to the product'after the application of the crossthreads 99. f

Also, the web or sheet components may be omitted entirely, thisresulting in the the thread-only product, which has particular utilityin instances where woven products such as gauze have heretofore beenused, consists merely in theV two sets 'f of strands adhesively attachedto each other at at least somel of their junctions.

For some applications, it is important that the strength of a product inits short dimension be as great as,1 or greater than, its strength inits long dimension.' f A typical example of a product of this type is aboxmakers 'tape' which is used to join the edges of a corner of acardboard box. This type of product can be made lon a machine of thetype illustrated in Figures 1 -and 2 by eliminating the main sheet 36and providing twoor more rolls of paper or other material incircumferentially spaced relation within the carrier 39. The resultingproductis illusproduction of a product of the type illustrated in Figure9. As shown in that ligure,

i Turningnow to the schematic showing in Figure ,11, the distances shownare identified as follows:

AB -is the effective width of the belt on a line parallel to the axis ofthe mandrel, this distance being equal to the pitch of the helical rib16;

BD is equal to the circumference of a right circular section of themandrel (simply the circumference of the mandrel if no belt is employed,or the outer circumference of the belt as it is trained about themandrel);

BG is the effective Width of the belt measured along a lineperpendicular to its length (or the width of the sheet if no belt isused);

' AD is the length of the helix, comprising one complete turn from apoint B around the mandrel to point A;

CF is the transverse width of the cross sheet;

'ACD isthe repeating length of the cross lay pattern, measured along thelength of the main sheet for the condition where the carrier makes onerevolution for each vadvance ofthe sheet through the distance CD;

i AE `is the opening available for cross laying, i. e., the availablespace on the main web on which the second web lcan be laid, and l i a isthe angular deviation between the direction of longitudinal movement ofthe second web and a perpendicular to the direction of longitudinalmovement of the first web, i. e., the angle between the edge of thesecond web or other medium and a perpendicular to the'edge or directionof movement of the rst web, when the second web is lin position on theiirst web; and

is the angle `between the mandrel axis and the direction of longitudinalmovement of the rst web or other medium. This angle is also the angle ofinclination of the edge of the supporting belt (or the rst medium, ifYthatmedium be of sheet material) to the line along which the belt (orthe first medium, if that medium be of sheet material) intersects themandrel.

Normally,l the width of the main sheet and cross sheet, and the 'angleofthe lay will be predetermined, and the factors to be determined will bethe inclination of the main web to the-mandrel, the diameter of themandrel, and theratio lof belt speed to the speed at which the crosslaid` material is applied to the mandrel. There are'practicallimitations in the design which must be taken intoconsideration. For example, if the angle of inclination of thesupporting surface tothe line of its intersection with the mandrel,angle 6 in Figure l1, is too large, the pull on the belt will be takenup along the mandrel and not by the belt. If the angle is too small, thebelt will slip off the mandrel. For practical perpendicular crosslaying, this angle will be in the range of from .to 60.

" For satisfactory operation at high speed, it will be found importantto provide special support means for the belt, or rst medium, as thatelement-is moved on the surface of the mandrel.V In the particularapparatus illustrated in the drawings, that support is provided .by anair cushion formed intermediate the inner surface of the belt or firstmedium and the outer surface of the mandrel. This will be described infurther detail in connection with Figures 12, 13 and 14,

. In the following analysis, it is assumed that the carrier for thecross laid medium makes one revolution for each repeating length of thecross lay pattern, represented by the length CD in Figure 1l. Thoseskilled in the art will appreciate that other speed relationships arepossible the practice of the present invention.

yFrom anV inspection of the angular relationships and the 'applicationof the law of sines, it will be seen that:

B G V cos B--BD (1) C'F=C'D cos a (2) .BG-:30me a (3) Applying the lawof sines:

CD BC' sin (0-a)- cos 6 Multiplying both sides by cos a and usingEquations 2 and 3:

so that the angle 6 may be calculated from the two web widths and theangle between the webs.

It will further be seen that:

AE=AC cos a (7) Applying the law of sines:

AC' BC sin (-0-l-a) "sin 0 Ac=Bo.- OS (0) (s) sin 0 Multiplying bothsides by cos a, and substituting Equations 3 and 7:

cos (0-a) Equation 9 gives the opening available for cross laying. Ifthe distance AE is less than the distance CF, then the cross web must besplit up into increments, and applied e in sequence, or the openingincreased by wrapping the belt another turn about the mandrel.

In the case of laying individual threads, instead of a cross web, itwill be seen that if N threads equally spaced by a distance S areemployed, Equation 6 will become:

l-I-BG sin a tan 0: BG cos a The following specific examples illustratethe application of these equations to specific cases.

Example I tan 0 (BG COS or) BG sin oz S tan 45[(40+0.5) cos 0]-(40+0.5)sin 0 0.2 v

Y N Y=i2'o`2.5 Strands rlvForconvenience;N-will betaken as 200.

'would be:

The angle 6 is then calculated for the Equation 10 as follows:

valueof from tan a: =0.9s765 Y The effective diameter, D, of themandrel. (actual diameter plus twice the thickness of the belt) mayVthen be calculated from Equation l:

BG 'lr COS/0 j Y Dfi- 18.11.9111.

Diameter of mandre1=1s119 inf-@5517.619 in.

i Example` Il LFor producing the same product as specifedqin Example* I,butfwhere the angle 0 between the -main sheet y andthe mandrel is to beabout 60, `the following values are obtained:

to be 0.5 inch4 as previously.

Using Equation 6:

tan 0: :1.7284

Ulla i' l tan 0-405- 098765 Solving for the mandrel ldiainetertrumVEquation Diameter of mandre1=l8.1l9- 0.y5=17.619 in.

lThe available opening in this case from Equation 9 fSince this valueexceeds the width-ofthe cross web, the

ldesired product can be obtained byusing a single roll of the cross web.

Example IV In this case, a cross web measuring 70'inches in width lwasto be laid at right angles tol a main web 40 inches in width, using vthesame ribwidth and belt thickness as pre- The mandrel diameter is then'calculated as' followsz" l0-5. :25.742im.

1r COS 6 Diameter=-742-0.5=25.242 in.`

The available opening, AE, is then calculated as follows:

Aar-S-aazlar, in.

sin 0 Since the available opening is slightly more than onethird thewidth of the cross web, the cross web would have to be laid in at leastthree parts,.as by slitting the 70 inches web into three equal strips,and laying them in -side-by-side-relationship along the main web as it.

moves about the mandrel.

Example V It was desired to use a sheet 40 inches wide, va rib 0.5' inchwide, a belt 0.025 inch thick, a spacing of 0.2 inch; The de betweenthreads, and a cross lay angle of sired angle of intersection (angle 0)was about 45.

The distance CF in Figure 1l in the case of strands is-` represented bythe repeating width of the cross lay...

Hence from Equation 5: v y I sin 45-30) 0.2N-(40+0.5) W

Choosing the convenient valueof =75, the repeating width of the crosslay is then 0.2=15 in.

l5-H405) sin 30"k r tall -m--LOO5O and i The diameter, D, is thenobtained from Equation 1::

1r COS 0 The actual diameter of the mandrel is then As previouslyindicated, the above examples are prodicated upon the use of a specificspeed ratio between the In the case of thread laying, the speedrelationships are usually supporting surface and the cross laid medium.

the easiest to vary in order to* change the angle of inclinationybetween the two surfaces. The following example illustrates the eiectof speed variation.

Example VI A A With the Vsame equipment as employed in Example I,thehcarrier made one revolution for every 40 inches ad- Vance ofthe webmaterial. VAssume now that the carrier is to make n revolutions for each40 inch advance of the web. Wirth this condition, it will be seen thatthe repeating length of the pattern will become:

40/n inches VReferring again toiFigure 1l, it will be 4observed that.

in this situation:

UniG-D and:

Y y f GD GG GD- CD;GD.".(T

rEquation 10 can be solved for tan 6 exactly as fol-4 f .35 lows:

thefeferebe? G D) t fthe spacing in the originalexample, the formula forthe'newspacing may be written;

i New spacing-1,(originalspacingyoixv (13) To illustrate -theabove' withspeciiic'examplesg'as'- sume that the carrier makes two' revolutionsfor"every 40 inch advance of the web in Example I. From Equation 12:

Assuming next that the carrier makes one-half a revolution for each 40inch advance;

GD tain CIT- l B G- In the special case where n,=J/z, itpwill beseenfrom Equation 12 that a=0. eos 44 38.6

Upon consideration of the several foregoing examples, it will beapparent that the following generali relationship exists: v

n;1 n(CD) (n-l') (CD) n BG BGV in which equation n is equal to thenumber of turns of the second medium which occur during each linearadvance of the rst medium, in the direction of movement of that medium,equal tothe transverse width of the second medium, and theAotherquantities are asjdened in the foregoing.

-It will also be apparent that thethread spacing S, in instances wherethe second medium comprises a series of longitudinally-extendingthreads, may1 be determined by the following formula:

Shaw

in which equation N is equal to the number of threads comprising thesecond medium,V and the other quantities are as defined previously. Aspreviously indicated, satisfactory operation of equip;V ment of thegeneral type described in the foregoing requires thatfthe support belt,or the medium which is trained abqutthe mandrelininstances Y where ,abelt is 'tan a: (145)A not used, shall move freely about the mandrel.This is especially, important in the high speed oper-ation of equipmentusing a support belt for the medium which is carried on the mandrel, asfor example, during the manufacture of crossedthread products of thegeneral type illustrated in Figure 9.

The only effective means so far devised for assuring free movement ofsuch a belt involves the provision of a cushion: of..air which floatsthe belt a short distance aboveuthe mandrel surface, anda mandreldesigned 4to operate in this manner is illustrated in Figures 12 and 13.It will be understood that the air-flotation type mandrel is suitablefor use in apparatus of the type illustrated in Figures 2 andv 8, aswell as other embodiments in accordance with the invention. It will alsobe understood that it may be advantageous, in certain instances,

' and the counter-sinking was at an angle of 118.

to use an air cushion or air otation mechanism in conjunction with oneor more of the supporting guides for the belt structure in thos'emechanisms which utilize a belt.

Themandrel 119 illustrated in Figures 12 and 13v includes Vvasuitable'tubular shell 121 of cylindrical form, which is closedat eitherend by an annular plate member 123, welded or otherwise affixed to theshell 121. If the mandrel 119 is intended for use in place of themandrel 14, it 4may include shaft sections 125 which extend axiallytherefrom; these may be provided by,a single, continuous shaft, or twostub shafts may be used. The outer Isurface of Athe tubular shell 121 isprovided with a helical groove '127, similar to the mandrel 14, withinwhich there is located a spline or key member 129, which serves as aguide means for defining the path of movement of thev belt'over themandrel surface.

In structures embodying a supporting belt, the spline member 129 shouldproject from the surface of the shell a distance approximately equal tothe thickness of the belt. The surfaces of the belt and the spline aredesirably polished, and may be plated with chromium or other metal, toprovide a very smooth, anti-friction surface.

'lfhe walls of .the shell 1 21are provided with a seriescedflcounter-spnk' openings 131, which communica .withjthe interiojrjofthe shell. In a particular structure which ha's'proven'especiallysatisfactory in use, the mandrel shell had a length of approximately '120 inches, and a diameter of 12.375 inches, this mandrel being adaptedtosupport a belt having a width of 27 inches which was trained about themandrel to provide 2 completely supported turns of the belt. The holeshad a diameter of IAS inch, and were spaced approximately 3% inchesapart, uniformly on the mandrel surface, so as to underlie' the belt inpositionthereon.'

In the mandrel having the dimensions stated above, there were 358holes-in the region of the mandrel engaged by the belt. Thecounter-sinking provided a maximum diameter at vthe outlet end oftheholes of 1/sjinch,

During operation, pressure airwas `admitted to the interior of themandrel so as to maintain the pressure inside the mandrel within therange of from about 3-5 lbs. per square inch, gauge. A single air inlet,such as illustrated at 133 in Figure 12,l is satisfactory for thispurpose. Underthe stated conditions, air will escape through thecounter-sunk, /airjdi'scharge openings 131 in' sufficient This willreduce the friction between the belt and the l:mandrel to a very lowvalue, and, as previously noted,y

the belt or the web medium. Also, when using the air` flotation mandrelin conjunctionwith a supporting belt of porous material, itis of someimportance that one surface of the belt; usually the outer surface,shall include a relatively non-porouslayer. This may, for example, be alayer of polyethylene, tetrafluorethylene, or other.suitablerriateri'al, ad'hesively attached to Ythe belt surface.This"noir-porous"layerfespeciallywhen it constitutes the outer layer andis made of a material such as polyethylene, ,orptetrafluorethylenqperforms 'a dual function. First, it facilitates the removal of thethread or other medium which ,is applied to-the belt `during operationof the apparatus, and in addition, it aids, in conjunction with theporous under layer, in accomplishing even flotation of the`belt on the`mandrel. One example of such a belt is illustrated at 135 in Figure 14,in which view the porous layer of the belt is shown at 137 and thenon-porous layer at 139. It will be understood that this belt can besubstituted for the belts 17 and 83 of the previously describedstructures.

In the foregoing, I have disclosed the features of a new, improvedmethod and apparatus for manufacturing a Wide variety of cross laid andreinforced products involving the use of mediums which may comprisesheet material of the woven, non-woven or felted type, in combinationwith other materials of this type or with threads. The invention alsomakes possible the manufacture of gauzelike materials, havingcharacteristics equal or superior to woven textile materials, at higherspeeds, at lesser cost, and with a number of important advantages ascompared with woven products. Any types of thread made from natural orartificial fibers or filaments, or combinations thereof, may be used.

I have also set forth in the foregoing variou-s of the importantmathematical relationships which exist and which should be followed inthe most efficient practice of the invention. In addition, I havedisclosed certain mechanical arrangements and structural combinations ofespecial advantage in carrying out the invention.

Various features of the invention believed to be new are set forth inthe accompanying claims.

I claim:

l. An apparatus for forming a continuous web product, comprising amandrel, a flexible endless belt having at least one complete helicalturn on said mandrel, means for depositing a first, elongated flexiblemedium on said belt, said first medium being carried by said belt aboutsaid mandrel, a rotatable carrier having an axis substantiallycoinciding with the axis of said mandrel, supply means for a second,elongated flexible medium mounted on said carrier, means for guidingsaid second flexible medium from said supply means over said firstflexible medium while said first flexible medium is passing over saidmandrel, the second flexible medium being applied in the form of a helixwhich is wrapped around said rst medium in such relationship that thelong dimension of said second medium is maintained at a uniform,substantial angle to the long dimension of said first medium in theregion where the mediums intersect, and means for cutting said secondmedium transversely of its long dimension after said second medium hasbeen applied to said first medium.

2. An apparatus for forming a continuous web product, comprising amandrel, a narrow, elongated guide strip attached to said mandrel anddefining a helical path around said mandrel, a flexible endless belthaving at least one complete helical turn on said mandrel, a portion ofsaid belt being within said helically disposed guide strip and guidedthereby, means for depositing a first, elongated flexible medium on saidbelt, said first medium being carried by said belt about said mandrel, arotatable carrier having an axis substantially coinciding with the axisof said mandrel, supply means for a second, elongated flexible mediummounted on said carrier, means for guiding said second flexible mediumfrom said supply means over said first flexible medium while said firstflexible medium is passing over said mandrel, the second flexible mediumbeing applied in the form of a helix which is wrapped around said firstmedium in such relationship that the long dimension of said secondmedium is maintained at a uniform substantial angle to the longdimensionofsa'id first mediumiin the region where the mediums intersect,means for-cutting said'se'cond medium trans-Y verselyoffits longdimension after said second medium has-been applied to said firstmedium, and means includingwa -source of `pressureair and-aplurality ofairl discharge openings providedin said mandrel for providing a cushionof airintermediate said -belt and said mandrelduringoperation-ofsaidapparatus, said belt being. of multi-layerconstruction and including at least one layer of non-porous material.

3. An apparatus for forming a reinforced web which comprises a mandrel,guide means on said mandrel, a flexible endless belt trained in ahelical form on said mandrel and guided thereon by said guide means,means formoving said belt along said mandrel, means for depositing asheet along said belt with the machine direction of said sheet lyingsubstantially lengthwise of said belt, said sheet being carried by saidbelt about said mandrel, a carrier having its axis substantiallycoinciding with the axis of said mandrel, means for feeding a pluralityof strands from said carrier about said sheet while said sheet is in ahelical form with the length of said strands being angularly disposedwith respect to the machine direction of said sheet, guide meansarranged to lay said strands in straight lines across said sheet, meanscausing relative movement between said carrier and said mandrel, andcutting means for cutting said strands lengthwise of said sheet aftersaid strands are laid over said sheet.

4. An apparatus for forming a reinforced web product having pliesthereof with the direction of maximum strength of one sheet being inangular relationship to the direction of maximum strength of another ofthe constituent sheets comprising a mandrel, a flexible endless belthaving at least one complete helical turn on said mandrel, means formoving said belt about said mandrel, means for depositing a first sheeton said belt, said sheet being carried by said belt about said mandrel,a rotatable carrier having an axis substantially coinciding with theaxis of said mandrel, a roll of sheet material carried by said carrier,means for guiding the sheet from said roll over said first sheet whilesaid first sheet is passing over said mandrel to provide a line oftangency between said sheets which is generally parallel to the axis ofsaid mandrel, and means for cutting said second sheet after said secondsheet has been deposited on said first sheet.

5. An apparatus for forming a reinforced web product comprising amandrel, a flexible endless belt having at least one complete helicalturn on said mandrel, means for moving said belt about said mandrel,means for depositing a first sheet along said belt with the line ofmaximum strength of said sheet lying substantially lengthwise of saidbelt, said first sheet being carried by said belt about said mandrel,rotary means associated with said mandrel, a roll of sheet materialcarried by said rotary means, said roll being oriented to apply a secondsheet onto said first sheet in a manner such that the direction ofmaximum strength of the second sheet is substantially at right angles tothe direction of maximum strength of said first sheet, means fo-rrotating said roll about an axis substantially coinciding with the axisof said mandrel, and cutting means operable to cut said second sheetcontinuously after said second sheet has been deposited on said firstsheet.

6. An apparatus for forming a laminated web product Y material carriedby said carrier in spaced relation to Vsaid mandrel, said roll'beingangularly disposed with respect to said mandrel to apply on said rstsheet, a web of sheet material whose machine direction is substantiallyat right angles to the machine direction of said first sheet withthesecond sheet intersecting said first sheet along a line which isgenerally parallel to the axis of said mandrel, and cutting meansoperable to cut said second sheet continuously after said second sheethas been deposited on said-rst sheet.

References Cited in the le of this patent UNITED STATES PATENTSv Brennan...e Sept. 30, 1919 Angier Mar. 2, 1920 Parker Feb. 5, 1935 Rowe Sept.3, 1940 Smith et al Aug. 13, 1946 Malmstrom Aug. 21; 1951 Jackson .fDec. 7, 1954

